Variable knitting machine drive



5 Sheets-Sheet l INVENTOR. Q11 4a 4' J24 M242- 6, 1966 R. SCHMIDTVARIABLE KNITTING MACHINE DR Filed Aug. 6, 1964 Aug. 30, 1966 R. SCHMIDTVARIABLE KNITTING MACHINE DRIVE Filed 6, 1964 5 Sheets-Sheet 2 /5a,

INVENTOR. I 161,14 f/z Infill Aug. 30, 1966 Filed Aug. 6, 1964 R.SCHMIDT VARIABLE KNITTING MACHINE DRIVE 5 Sheets-Sheet 3 A 1/7 I I73 04770 70.6 if 706 y 70? i l l I I I] I 707 I03 [02 3c 7 6 II? INVENTOR .L.La i MM/W United States Patent 3,2622% VAREAELE KNKTTENG MAfiHlNE DRIVERichard Schmidt, Stuttgart-Vaihingen, Germany, assignor to Franz MuratG.m.b.H., Stnttgart-Vaihingen, Germany Filed Aug. 6, 1964, Ser. No.387,832 Claims priority, application Germany, Aug. 7, 1963, M 57,748 14Claims. (QB. 74-675) The present invention relates to a knitting machinedrive, and more particularly to a circular knitting machine providedwith an infinitely variable drive.

Circular knitting machines operate at a predetermined high workingspeed, which corresponds to a maximum rotary speed of the needlecylinder, and in interlock machines also to a maximum speed of the dial.However, it is sometimes necessary to reduce the rotary speed of theneedles in the cylinder, or of the needle cylinder and dial, to such alow speed that the operation of the needles is slowed down to such anextent that it can be observed by the person operating the machine.

If the machine is comparatively small, a drive wheel or gear is manuallyturned, and if the machine has a large diameter for example an interlockmachine, a transmission provided with hand wheels acts on the turnableelements of the machine so that the same can be slowly turned. Theperson observing the operation of the needles at low speed must, at thesame time, turn the hand wheel, which requires great force, andmoreover, the operating person is compelled to stand in the proximity ofthe hand wheel, while observation of needles at another point of thediameter of the machine may be necessary. Even if several hand wheelsare provided, it is not possible to mount a sufficient number of handwheels and associated transmissions around the periphery of the machineto permit the observer to see all needles during the slow motionoperation. Due to the fact that the operating person must apply greatforce to turn the machine, he cannot concentrate on the observation ofthe needle operation. Another disadvantage of the known manualoperations of knitting machines resides in that the knitting machine canbe turned substantially at one low speed. It is not possible to vary thespeed of the needle operation during observation while the machine ismanually turned.

It is one object of the invention to overcome the disadvantages of knownconstructions for operating machines, particularly knitting machines, ata very low speed, and to provide means for operating a machine by amotor at a very low speed, so that no manual operation is requiredduring observation of machine operations.

Another object of the invention is to provide means for driving amachine, particularly a circular knitting machine, in oppositedirections at an infinitely variable speed, which can be adjustedbetween a normal high operating speed, and a very low speed at whichmachine operations, and particularly needle operations can be observedin slow motion.

Another object of the invention is to provide means for driving aknitting machine at an infinitely variable speed including a very lowspeed, and to provide means for adjusting the rotary speed of themachine at several points around the circumferential periphery of themachine so that the operator controlling the speed of the machine canobserve any selected part of the machine from suitable points at theperiphery of the machine.

Another object of the machine is to provide means for Biddild normallypreventing an adjustment of the drive to a speed exceeding a desiredworking speed of the machine.

With these objects in view, the present invention relates to aninfinitely variable drive for a machine, particularly a circularknitting machine. One embodiment of the invention comprises a drivemotor, an infinitely variable transmission including an output shaft fordriving the machine, and a movable control element for varying the speedof the output shaft; a reversible control motor for operating thecontrol element of the variable transmission; and manually operableswitching means, preferably provided on the housing of the machine incircumferentially spaced position, and electrically connected with thecontrol motor for starting and reversing the same. By operating theswitching means, which preferably include pairs of switches for drivingthe control motor in one or the other direction of rotation, theoperator can reduce and increase the speed of the machine, andparticularly can cause rotation of the needle cylinder and operations ofthe needles at such a low speed that the function of the needles can beclearly observed,

If the control motor is disconnected and stopped by operation of theswitching means in any position, the variable transmission will drivethe knitting machine at a corresponding speed which may be the normalhigh working speed or a very low observation speed.

The switching means do not require additional space, since theconnectors and cables can be easily mounted within the housing of themachine so that only the manually operated switches have to be mountedon peripheral portions of the housing. The circumferential spacing ofthe manually operated switches would be selected to permit the operatorto observe the machine operation from as many points around theperimeter of the machine as is necessary. In this manner, the speed ofthe machine can be varied, or maintained at a desired low level at anyobservation point around the circumference of the machine.

In the preferred embodiment of the invention, the control motor operatesan actuating member by which two limit switches are actuated to causestopping of the control motor so that the control element of thevariable transmission also stops resulting in rotation of the knittingmachine at a certain terminal speed. The two limit switches determinethe speed limits of the machine corresponding to the desired highworking speed and to a very low observation speed. Preferably adjustingmeans are provided for adjusting the position of the limit switch whichcontrols the maximum speed of the knitting machine so that the workingspeed can be selected.

It is advantageous to lock the limit switch arrangement in a selectedposition corresponding to the maximum working speed so that unauthorizedpersons cannot increase the working speed of the machine beyond thespeed limit set by the supervisor.

The limit switches also prevent damage to the transmission since thecontrol element by which the speed of the output shaft of thetransmission is determined, cannot be moved by the control motor beyondits normal end positions corresponding to the limits of adjustment ofthe variable transmission.

Several switch units are provided around the circumfcrence of themachine housing, each switch unit including first and second manuallyoperable switches which cause, respectively, increase or decrease of thespeed of the knitting machine when actuated, and stopping of the controlmotor and continued operation of the machine at a constant speed, whenreleased by the operator.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claim-s. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, Willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is an elevation, partially in section, illustrating oneembodiment of the invention;

FIG. 2 is a diagram illustrating the electric circuit of one embodimentof the invention;

FIG. .3 is an elevation, partially in axial section, illustnating aninfinitely variable transmission used in the drive arrangement of thepresent invention; and

FIG. 4 is an axial sectional view of a circular knitting machineprovided with the apparatus of the invention.

Referring now to the the drawing, and infinitely variable transmission2, having an output shaft 4, and a drive motor 1 driving the input shaft10!, see FIG. 3, of the variable transmission 2, are mounted by means ofa flange on the stationary housing 3 of the machine. Output shaft 4 isconnected with the main shaft of the machine and drives, for example,the needle cylinder of a circular knitting machine, and also the dial ofan interlock machine. As best seen in FIG. 4, a needle cylinder ring 101is secured to the housing 3 by screws 102. Ring 101 turnably supportsthe lower end of the needle cylinder 103 which has axially extendingchannels for guiding cylinder needles 104 which are reciprocated by cams105 of the stationary cam cylinder 106. Oam cylinder 106 is secured byscrews 107 to a stationary ring 108 secured by screws 109 to housing 3which includes supporting legs, not shown.

A dial 110 supports dial needles 111 for radial movement. Dial cams 112on a dial cam plate 113 cooperate with the dial needles 111. Dial 110 isrotated in syn chronism with needle cylinder 103.

The lower part of needle cylinder 103 has a gear ring meshing with agear 114. Gear 114 is secured by a key 115 to the vertical shaft 116which is mounted in a bearing 30 of housing 3. The lower end of shaft116 is secured by a key 117 to a bevel gear 118 which meshes with abevel gear 119 secured by a key 120 to a horizontal shaft 121 which isturnable in a bearing 122, but nonmovable in axial direction due to aring 123 fixed on shaft 121. Bearing 122 is secured by screws 124 to thehousing 3.

Housing 3 has a flange 3a to which a part 125 of the casing oftransmission 2 is secured. Shaft 4, to which bevel gear 127 is securedby key 126, is mounted in a bearing of part 125. Bevel gear 127 mesheswith bevel gear 128 on shaft 121, so that the needle cylinder, andthereby the dial, are driven from output shaft 4. A control element,shown to be the shaft with a bevel gear 6 controls the ratio of theinfinitely variable transmission 2, bevel gear 6 meshing with a bevelgear 9 on the output shaft 8a of a reversible electric control motor 8which is mounted on the housing of transmission 2 by means of a bracket7.

Any variable transmission may be used in the drive arrangement of theinvention, and FIG. 3 illustrates an infinitely variable tnansmission 2which is available in the trade. The drive shaft 1a of transmission 2carries a frusto-conical friction wheel 34, which is in frictionalengagement with a plurality of planetary frusto-conical friction wheels33 which are rotatable about the respective axes thereof, and alsomounted on a spider structure for revolving about the axis of shaft 1a.An outer friction ring 32 has a cylindrical inner surface whose axiscoincides with the axis of shaft 1a and of output shaft 4. A frictionwheel 4a on shaft 4 is in frictional engagement with the cylindricalinner surface of the outer friction ring 32. Friction ring 32 has aninner annular projection 32a in frictional engagement with conicalfriction surfaces 33a of the planetary friction wheels 33. When ring 32is shifted in axial direction, the ratio of the transmission isinfinitely and gradually varied so that the rotary speed of the outputshaft 4 is varied between a minimum and a maximum.

The adjustment of friction ring 32 is accomplished by turning movementof the control element 5, 6. Shaft 5 carries a gear 36 cooperating witha gear portion on a cylindrical member 37, which is not movable in axialdirection thereof, but is turn-able about the axis of shaft 101 and hasinner threads meshing with an outer thread 32d on a cylindrical member32b which is surrounded by member 37 and is non-turnably mounted. A ballbearing 32c coaxial with shaft 1a connects member 32b with ring 32 formovement in axial direction but permits rotation of ring 32 in member321) so that axial movement of ring 32, and adjustment of thetransmission are effected when control motor 8 rotates shaft 5 throughmeshing bevel gears 9 and 6. In all axially shifted positions offriction ring 32, friction wheel 40 with output shaft 4 are driven atdifferent speeds depending on the position of the annular projection 32aon the friction cone 33a.

When control motor 8 rotates in one direction, the speed of output shaft4, and of the knitting machine is increased from a minimum to a maximum.When control motor 8 rotates in the opposite direction, the transmissionis adjusted by control element 5, 6 to reduce the speed of output shaft4 from a maximum to a minimum.

The electrical circuit of the apparatus will now be describe-d withreference to FIG. 2. Output shaft 8a and bevel gear 9 of control motor 8are not only connected to control element 5, 6 of the variabletransmission but also to the shaft 10 of a turnable actuating member 11.It will be understood that actuating member 11 is turnable through anangle substantially corresponding to the angle through which controlelement 5, 6 turns during adjustment of the transmission 2 from maximumratio to minimum ratio. It is assumed that control motor 8 effects areduction of the speed when turning in clockwise direction, as viewed inFIG. 2, and an increase of the speed when turning in counter-clockwisedirection. Shaft 10 carries a bevel gear, not shown, meshing with bevelgear 9 so as to be rotated in synchronism with control element 5.

Limit switches 12 and 13 are disposed in the circular path of actuatingmember 11 and actuated by the same in two end positions. Limit switches12 and 13 are connected by a cable 14 to one terminal of a battery 16,or corresponding source of a low voltage whose other terminal isconnected to ground or mass. A cable 15 including a plurality ofconductors including conductors 24, 25 which are connected to the limitswitches, and other conductors 24a, 25a, is mounted on the housing ofthe knitting machine extending around the periphery thereof. Cable 15 ispreferably located in an annular covered or otherwise closed cavityextending around the housing of the machine.

At places spaced around the circumference of the knitting machine,switch units 100, a and so forth, for example, 12 units are provided andconnected to cable 15. The positions of the switch units are selected sothat an operator can observe any part of the machine while standing inthe proximity of one of the switch units.

Each switch unit 100, 100a includes a first manually operated switch 21,210, a second manually operated switch 22, 220, a first signal lamp 26,26a connected to conductor 25 and to mass or ground M, and a secondsignal lamp 27, 27a connected to conductor 24 and to mass M.

Control motor 8 has three leads 8' which are, respectively, connected tothree contacts of a relay 18 and to three contacts 19a of a relay 19,the relay contacts 18a and 19a being connected to a source of powervoltage 17 in such a manner that upon closing of relay contacts 18::control motor 8 will turn in counter-clockwise direction so that therotary speed of output shaft 4 of the transmission 2 is increased, whileclosing of contacts 19a will effect turning of control motor 8 inclockwise direction and a reduction of the rotary speed of output shaft4. Relays 18c and 190 are connected to ground M and also operatenormally closed relay contacts 18b and 191) which are, respectively,connected with windings 19c and 18c. All switches 21, 21a and so forthare connected to each other by conductor 24a and to relay contact 1% byconductor 21). All switches 22 are connected to each other by aconductor 25a, and to relay contact 18b by a conductor 23. Relaycontacts 181) and 1% are, respectively, connected in series withwindings 19c and 180 of relays 18 and 19. All switches 21 are alsoconnected by conductor 24 to limit switch 12 and all switches 22 arealso connected by conductor 25 to limit switch 13. Switches 21, 21a and22, 22a etc. are normally open, and can be closed by a manual operation,but are biased by springs, not shown, to return to the normal openposition upon release by the operator. 7

The arrangement is operated as follows: The operator may stand at anyselected place around the periphery of the knitting machine in theregion of one of the switching units 100, hr: of which, for example,twelve may be provided. The position is selected by the operator so thathe has a good view at a particular part of the machine which he wishesto observe during operation at a very low speed. The operator depressesmanually the button of the respective switch 22, 22a of the respectiveselected unit, so that the relay winding 19a is energized causingturning of control motor 8 in clockwise direction and adjustment of thevariable transmission 2 so that the rotary speed of output shaft 4 andof the needle cylinder of the machine is reduced. The current flows frombattery 16 through conductor 14, limit switch 13, conductor 25, switch22, conductor 23, and the normally closed relay contact 18b to relaywinding 19c and energizes the same so that relay contacts 194: close andcause rotation of control motor 8 in clockwise direction. When actuator11 engages and opens limit switch 13, the cricuit is interrupted, relay19 de-energized and relay contacts 1% opened so that control motor 8stops in a position in which the variable transmission 2 has beenadjusted by control elements 5, 6 in such a manner that output shaft 4drives the needle cylinder at an extremely low speed at whichobservation of the needle operations by the operator is easily possible.The operator may also observe the operations of needles during thegradual reduction of the rotary speed of the needle cylinder.

In the event that the operator releases the button of the respectiveswitch 22 while actuator member 11 and control elements 5, 6 oftransmission 2 are in an intermediate position, control motor 8 stops inan intermediate position, and the needle cylinder of the knittingmachine is driven at an intermediate speed. When the operator againdepresses the button of switch 22, the speed is further reduced from theintermediate speed to a lower speed so that observation of theoperations at different speeds is possible.

When it is desired to increase the speed of the machine again, switch 21is actuated, and relay 18 is energized. The current flows from battery16, through conductor 14, limit switch 12, conductor 24, switch 21,conductor 29, the normally closed relay contact 1% to the relay winding18c so that contacts 18a close and connect control motor S in such amanner to the power voltage 7 that control motor 8 rotates in theopposite counter-clockwise direction whereby control elements 5, 6 oftransmission 2 is adjusted to increase the speed of output shaft 4 andof the knitting machine. When switch 21 is released, control motor 8stops in an intermediate position, since the relay winding 18c isdisconnected from battery 16. If switch 21 is held depressed untilactuating member 11 engages and opens limit switch 12, relay 18 isde-energized, opens contacts 18a, and control motor 8 is stopped in aposition in which control element 5, 6 has adjusted transmission 2 todrive output shaft 4 and the knitting machine at a high speedcorresponding to the normal working speed of the knitting machine. Inthis manner the speed of the machine can be adjusted from an extremelylow speed to the normal working speed.

Limit switch 12, whose position along the circular path of movement ofactuating member 11 determines the highest speed of the machine, ismovable along this circular path, so that its position can be adjusted.Consequently, the machine will be automatically stopped at the desiredhigh working speed, although the variable transmission 2 would permitfurther adjustment resulting in an even higher speed of the knittingmachine, which higher speed, however, is not desired for normaloperations. The adjusting means by which the position of limit switch 12can be adjusted and secured in an adjusted position, is enclosed in acover provided with locking means for preventing access by unauthorizedpersons to the adjusting means of limit switch 12. In this manner,adjusting of the knitting machine to an extremely high speed exceedingthe normal high working speed can be prevented by a supervisor. Whilethe output of the machine may be increased by such an excessive speed,it is in the interest of safety of operations to run the machine at aselected high working speed, which should not be exceeded.

While switch 22, 22a is closed, signal lamp 26, 26a is illuminated bycurrent flowing through conductor 25. While switch 21 is actuated,signal lamp 27 is illuminated by current flowing through conductor 24.The signal lamps are extinguished when the respective correlated limitswitches 12 and 13 open, so that illuminated signal lamps 26 and 27,which may have different colors, respectively indicate a decrease orincrease or the rotary speed of the knitting machine during a period ofadjustment of control element 5, 6 and variable transmission 2.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofadjustable drives of machines differing from the types described above.

While the invention has been illustrated and described as embodied in amotor-driven infinitely variable transmission for reducing the speed ofa circular knitting machine to an extremely low speed permittingobservation of knitting operations, it is not intended to be limited tothe details shown, since various modifications and structural changesmay be made without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. Control apparatus for a machine of the type described, comprising, incombination, a drive motor; an infinitely variable transmissionincluding an output shaft for driving the machine and a movable controlelement for varyin the speed of said output shaft; a reversible controlmotor connected to said control element for operating the same; andmanually operable switching means electrically connected with saidcontrol motor for starting, stopping, and reversing the same so that thespeed of said machine is selectively increased or reduced, and can beset to any selected speed by stopping said control motor.

2. Control apparatus for a knitting machine having a housing,comprising, in combination, a drive motor; a variable transmissionincluding an output shaft for driving the machine and a movable controlelement for varying the speed of said output shaft; a reversible controlmotor connected to said control element for operating the same; andmanually operable switching means including a plurality of switch unitsmounted on said housing spaced about the periphery thereof to permitobservation of different parts of the machine, each unit beingelectrically connected with said control motor for starting, stopping,and reversing the same so that the speed of said machine is selectivelyincreased or reduced, and can be set to any selected speed by stoppingsaid control motor.

3. Control apparatus for a circular knitting machine having a housing,comprising, in combination, a drive motor; a variable transmissionincluding an output shaft for driving the machine and a movable controlelement for varying the speed of said output shaft; a reversible controlmotor connected to said control element for operating the same; andmanually operable switching means including a plurality of switch unitsmounted on said housing circumferentially spaced about the peripherythereof, each unit including a first switch for causing rotation of saidcontrol motor in one direction of rotation and a second switch forcausing rotation of said control motor in the opposite direction, saidswitches being electrical-1y connected with said control motor forstarting, stopping, and reversing the same so that the speed of saidmachine is selectively increased or reduced, and can be set to anyselected speed by stopping said control motor.

4. Control apparatus for a machine, comprising, in combination, a drivemotor; an infinitely variable transmission including an output shaft fordriving the machine and a movable control element for varying the speedof said output shaft; a reversible control motor connected to saidcontrol element for operating the same; manually operable switch meanselectrically connected with said control motor for starting, stopping,and reversing the same so that the speed of said machine is selectivelyincreased or reduced, and can be set to any selected speed by stoppingsaid control motor; a movable actuator member driven by said controlmotor to move in opposite directions; and a pair of limit switchesdisposed spaced along the path of movement of said actuating member soas to be actuated by the same, each of said limit switches beingconnected to said control motor for stopping the same, when actuated sothat the machine operates at a maximum permissible speed or at a minimumspeed permitting observation of moving parts of the machine.

5. Control apparatus for a knitting machine having a housing,comprising, in combination, a drive motor; an infinitely variabletransmission including an output shaft for driving the machine and amovable control element for varying the speed of said output shaft; areversible control motor connected to said control element for operatingthe same; manually operable switching means including a plurality ofswitch units mounted on said housing positioned to permit observation ofdifferent parts of the machine, each unit being electrically connectedwith said control motor for starting, stopping, and reversing the sameso that the speed of said machine is selectively increased or reduced,and can be set to any selected speed by stopping said control motor; amovable actuator member driven by said control motor to move in oppositedirections; a pair of limit switches disposed spaced along the path ofmovement of said actuating member so as to be actuated by the same, eachof said limit switches being connected to said control motor forstopping the same, when actuated; and adjusting means for moving one ofsaid limit switches along said path and for securing the same in anadjusted position whereby one end position of said actuator member andone speed limit of said knitting machine are determined so that themachine operates at a maximum permissible speed or at a minimum speedpermitting observation of moving parts of the machine.

6. Control apparatus for a knitting machine having a housing,comprising, in combination, a drive motor; an infinitely variabletransmission including an output shaft for driving the machine and amovable control element for varying the speed of said output shaft; areversible control motor connected to said control element for operatingthe same; manually operable switching means including a plurality ofswitch units mounted on said housing positioned to permit observation ofdifferent parts of the machine, each unit being electrically connectedwith said control motor for starting, stopping, and reversing the sameso that the speed of said machine is selectively increased or reduced,and can be set to any selected speed by stopping said control motor; amovable actuator member driven by said control motor to move in oppositedirections; a pair of limit switches disposed spaced along the path ofmovement of said actuating member so as to be actuated by the same, eachof said limit switches being connected to said control motor forstopping the same, when actuated, adjusting means for moving one of saidlimit switches along said path and for securing the same on an adjustedposition whereby one end position of said actuator member and one speedlimit of said knitting machine are determined so that the machineoperates at a maximum permissible speed or at a minimum speed permittingobesrvation of moving parts of the machine; and locking means forlocking said adjusting means in adjusted positions of said actuatormember so that operation of said locking means is required for changingsaid speed limit of the machine.

7. Control apparatus for a circular knitting machine having a housing,comprising, in combination, a drive motor; an infinitely variabletransmission including an output shaft for driving the machine and amovable control element for varying the speed of said output shaft; areversible control motor connected to said control element for operatingthe same; manually operable switching means including a plurality ofswitch units mounted on said housing circumferentially spaced about theperiphery of the same to permit observation of different parts of themachine, each unit being electrically connected with said control motorfor starting, stopping, and reversing the same so that the speed of saidmachine is selectively increased or reduced, and can be set to anyselected speed by stopping said control motor; a movable actuator memberdriven by said control motor to move in opposite directions; and a pairof limit switches disposed spaced along the path of movement of saidactuating member so as to be actuated by the same, each of said limitswitches being connected to said control motor for stopping the same,when actuated so that the machine operates at a maximum permissiblespeed or at a minimum speed permitting observation of moving parts ofthe machine.

8. Control apparatus for a circular knitting machine having a housing,comprising, in combination, a drive motor; an infinitely variabletransmission including an output shaft for driving the machine and amovable control element for varying the speed of said output shaft; areversible control motor connected to said control element for operatingthe same; manually operable switching means including a plurality ofswitch units mounted on said housing, circumferentially spaced about theperiphery of the same to permit observation of different parts of themachine, each unit being electrically connected with said control motorfor starting, stopping, and reversing the same so that the speed of saidmachine is selectively increased or reduced, and can be set to anyselected speed by stopping said control motor; a movable actuator memberdriven by said control motor to move in opposite directions; :a pair oflimit switches disposed spaced along the path of movement of saidactuating member so as to be actuated by the same, each of said limitswitches being connected to said control motor for stopping the same,when actuated so that the machine 0perates at a maximum permissiblespeed or at a minimum speed permitting observation of moving parts ofthe machine; and adjusting means for moving one of said limit switchesalong said path and for securing the same in an adjusted positionwhereby one end position of said actuator member and one speed limit ofsaid knitting machine are determined.

9. Control apparatus for a knitting machine, comprising, in combination,a drive motor; a variable transmission having an output shaft fordriving the knitting machine and having a turntable control element forvarying the rotary speed of said output shaft, said control elementhaving two end positions corresponding to a maximum speed and to aminimum speed of said output shaft and of the knitting machine; areversible control motor connected to said control element for turningthe same in opposite directions, said control motor having leads; firstand second control relays, each relay having a winding and a pluralityof first contacts connected with said leads so that said control motorrotates in opposite directions when one or the other of said relaywindings is energized; and at least one of switching unit includingfirst and second manually operated switches connected with said relaywindings so to energize and deenergize the same whereby the direction ofrotation of said control motor is reversed by actuation of said first orsecond switches, respectively, and the speed of the machine isselectively increased or decreased, and whereby the machine can be setto any selected speed by deenergizing the respective relays and stoppingsaid control motor.

1d. Control apparatus for a knitting machine, comprising, incombination, a drive motor; a variable transmission having an outputshaft for driving the knitting machine and having a turnable controlelement for varying the rotary speed of said output shaft, said controlelement having two end positions corresponding to a maximum speed and toa minimum speed of said output shaft and of the knitting machine; areversible control motor connected to said control element for turningthe same in opposite directions, said control motor having leads; firstand second control relays, each relay having a winding and a pluralityof first contacts connected with said leads so that said control motorrotates in opposite directions when one or the other of said relaywindings is energized; a plurality of switching units positioned topermit observation of different pants of the machine, each includingfirst and second manually operated switches connected with said relaywindings so to energize and deenergize the same whereby the direction ofrotation of said control motor is reversed by actuation of said first orsecond switches, respectively, and the speed of the machine isselectively increased or decreased, and whereby the machine can be setto any selected speed by deenergizing the respective relays and stoppingsaid control motor; a turnable actuator member driven by said controlmotor to turn in opposite directions; and a pair of limit switchesdisposed along the path of movement of said actuator member so as to beactuated by the same, each of said limit switches being connected withone of said relay windings to de-energize the same in end positions ofsaid actuating member whereby said relay contacts are opened and saidcontrol motor stopped so that the rotary speed of the machine cannotexceed selected maximum and minimum speeds, the minimum speed beingselected to permit observation of moving parts of the machine.

ll. Control apparatus for a knitting machine, comprising, incombination, a drive motor; a variable transmission having an outputshaft for driving the knitting machine and having a turnable controlelement for varying the rotary speed of said output shaft, said controlelement having two end positions corresponding to a maximum speed and toa minimum speed of said output shaft and of the knitting machine; areversible control motor connected to said control element for turningthe same in opposite directions, said control motor having leads; firstand second control relays, each relay having a winding and a pluralityof first contacts connected with said leads so that said control motorrotates in opposite directions when one or the other of said relaywindings is energized; and a plurality of switching units positioned topermit observation of different par-ts of the machine, each includingfirst and second manually operated switches connected with said relaywindings so to energize and deenergize the same whereby the direction ofrotation of said control motor is reversed by actuation of said first orsecond switches, respectively, and the speed of the machine isselectively increased or decreased, and whereby the machine can be setto any selected speed by deenergizing the respective relays and stoppingsaid control motor, said first and second switches being biased toassume upon release of the operator a normal position in which saidrelay windings are de-energized.

12. An arrangement as set forth in claim 11 including a pair of signallamps connected with said limit switches and said first and secondswitches and being illuminated when one of said relays is energized toindicate turning of said control motor and adjustment of saidtransmission in opposite directions, respectively.

13. Control apparatus for a knitting machine having a housing,comprising, in combination, a drive motor; a variable transmissionhaving an output shaft for driving the knitting machine and having aturnable control element for varying the rotary speed of said outputshaft, said control element having two end positions corresponding to amaximum speed and to a minimum speed of said output shaft and of theknitting machine; a reversible control motor connected to said controlelement for turning the same in opposite directions, said control motorhaving leads; first and second control relays, each relay having awinding and a plurality of first contacts connected with said leads sothat said control motor rotates in opposite directions when one or theother of said relay windings is energized; a plurality of switchingunits spaced about said housing to permit observation of different partsof the machine, each including first and second manually operatedswitches connected with said relay windings so to energize anddeenergize the same whereby the direction of rotation of said controlmotor is reversed by actuation of said first or second switches,respectively, and the speed of the machine is selectively increased ordecreased, and whereby the machine can be set to any selected speed bydeenergizing the respective relays and stopping said control motor, saidfirst and second are de-energized; a turnable actuator member driven bysaid control motor to turn in opposite directions; and a pair of limitswitches disposed along the path of movement of said actuator member soas to be actuated by the same, each of said limit switches beingconnected with one of said relay windings to de-energize the same in endpositions of said actuating member whereby said relay contacts areopened and said control motor stopped so that the rotary speed of themachine cannot exceed selected maximum and minimum speeds, positioned topermit observation of different parts of the machine.

14. Control apparatus for a knitting machine having a housing,comprising, in combination, a drive motor; a variable transmissionhaving an output shaft for driving the knitting machine and having aturnable control element for varying the rotary speed of said outputshaft, said control element having two end positions corresponding to amaximum speed and to a minimum speed of said output shaft and of theknitting machine; a reversible control motor connected to said controlelement for turning the same in opposite directions, said control motorhaving leads; first and second control relays, each relay having awinding and a plurality of first contacts connected with said leads sothat said control motor rotates in opposite directions when one or theother of said relay windings is energized; and a plurality of switchinguni-ts mounted on said housing spaced circumferentially about theperiphery thereof, each including first and second manually operatedswitches connected with said relay windings so to energize anddeenergize the same whereby the direction of rotation of said controlmotor is reversed by actuation of said first or second switches,respectively, and the speed of the machine is selectively increased ordecreased, and whereby the machine can be set to any selected speed bydeenergizing the respective relays and stopping said control motor, saidfirst and second switches being biased to assume upon release of theoperator a normal position in which said relay windings arede-energized.

References Cited by the Examiner UNITED STATES PATENTS 2,051,553 8/1936Fleischel 74472.3 2,171,993 9/1939 Reichelt 74796 3,129,598 4/1964 Buss.

FOREIGN PATENTS 780,662 8/ 1957 Great Britain.

10 DAVID J. WILLIAMOWSKY, Primary Examiner.

RUSSELL C. MADER, Examiner.

'P. C. FAW, L. H. GERIN, Assistant Examiners.

1. CONTROL APPARATUS FOR A MACHINE OF THE TYPE DESCRIBED, COMPRISING, INCOMBINATION, A DRIVE MOTOR; AN INFINITELY VARIABLE TRANSMISSIONINCLUDING AN OUTPUT SHAFT FOR DRIVING THE MACHINE AND A MOVABLE CONTROLELEMENT FOR VARYING THE SPEED OF SAID OUTPUT SHAFT; A REVERSIBLE CONTROLMOTOR CONNECTED TO SAID CONTROL ELEMENT FOR OPERATING THE SAME; ANDMANUALLY OPERABLE SWITCHING MEANS